EP0332300B1 - Procédé et dispositif pour la mesure d'un intervalle entre deux objets - Google Patents

Procédé et dispositif pour la mesure d'un intervalle entre deux objets Download PDF

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Publication number
EP0332300B1
EP0332300B1 EP89301473A EP89301473A EP0332300B1 EP 0332300 B1 EP0332300 B1 EP 0332300B1 EP 89301473 A EP89301473 A EP 89301473A EP 89301473 A EP89301473 A EP 89301473A EP 0332300 B1 EP0332300 B1 EP 0332300B1
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EP
European Patent Office
Prior art keywords
wafer
mask
light
fresnel zone
light beam
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EP89301473A
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German (de)
English (en)
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EP0332300A3 (en
EP0332300A2 (fr
Inventor
Mitsutoshi Ohwada
Masakazu Matsugu
Shigeyuki Suda
Minoru Yoshii
Yukichi Niwa
Noriyuki Nose
Kenji Saitoh
Masanobu Hasegawa
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Canon Inc
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Canon Inc
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Publication of EP0332300A3 publication Critical patent/EP0332300A3/en
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F9/00—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically
    • G03F9/70—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically for microlithography
    • G03F9/7003—Alignment type or strategy, e.g. leveling, global alignment
    • G03F9/7023—Aligning or positioning in direction perpendicular to substrate surface
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F9/00—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically
    • G03F9/70—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically for microlithography
    • G03F9/7049—Technique, e.g. interferometric

Definitions

  • This invention relates to a method and apparatus for measuring an interval between two objects with high precision, which is particularly suitably usable in a semiconductor microcircuit device manufacturing apparatus, for example, to measure a gap or interval between a mask and a wafer for control of the same to a desired value.
  • FIG. 1 is a schematic view of a gap measuring device as proposed in Japanese Laid-Open Patent Application, Laid-Open No. Sho 61-111402.
  • a mask M (first object) and a wafer W (second object) are disposed opposed to each other, and by using a lens L1 a light is focused at a point Ps which is between the mask M and the wafer W.
  • the light is reflected by the mask M surface and by the wafer W surface, and the reflected lights are projected and focused by another lens L2 at points P W and P M on a screen S surface.
  • the gap or interval between the mask M and the wafer W can be measured by detecting the interval between the light spots P W and P M on the screen S surface.
  • each of the reflected lights from the mask and the wafer bears only the information related to the position of the mask or wafer.
  • two lights are necessary for the gap measurement. This is complicated.
  • German Patent No. DE-A-3719538 discloses a device for measuring the distance between two plate-like objects, as for instance a mask and a wafer.
  • a device for measuring the distance between first and second plate-like objects comprising a light source for projecting a light beam upon the first object and thereafter projected upon the second object, and a photodetector for detecting the position of incidence, upon its detection surface, of the light beam having been reflected by the second object; characterised by an optical element in the form of a diffraction element or Fresnel zone plate positioned on said first object so that the light beam detected by said photodetector is a light beam having been deflected by said optical element either upstream or downstream of the reflection position on the second object with regard to the beam direction, whereby the position of incidence of the light beam on the detection surface of the photodetector varies with the distance between the two objects, and a signal processor including means for receiving the output from the photodetector and for generating a signal representing relative displacement between said objects and means for comparing said generated signal with a reference signal corresponding to a predetermined distance between said objects
  • the first and second objects are respectively a pattern mask and a wafer, characterised by means for aligning the mask and the wafer on the basis of the distance determination, and a printing system for printing a pattern of the mask on the wafer.
  • a semiconductor device manufacturing method comprising the steps of: providing a mask having a pattern and an optical element in the form of a diffraction element or Fresnel zone plate on said first object; providing a wafer; projecting a light beam upon the mask and the wafer; detecting the position of incidence, upon a predetermined plane, of the light beam having been reflected by the wafer and having been deflected by the optical element of the mask either upstream or downstream of the reflection position with regard to the beam direction; determining the distance between the mask and the wafer on the basis of the detection by means of a signal processor which includes means for generating a signal representing relative displacement between said mask and wafer and means for comparing said signal with a reference signal corresponding to a predetermined distance between said mask and wafer; aligning the mask and the wafer on the basis of the determination by said signal processor; and thereafter effecting printing the pattern of the mask on the wafer.
  • Figure 1 is a schematic view of an optical arrangement, for explicating the principle of an interval measuring method of known type.
  • Figure 2 is a schematic view of an optical arrangement according to a first embodiment of the present invention.
  • Figure 3 is a schematic and perspective view showing a major portion of the first embodiment, around used physical optic elements.
  • Figure 4A is a plan view of a used physical optic element
  • Figure 4B is a representation of an optical path as viewed in the direction of an arrow B.
  • Figure 4C is a representation of an optical path as viewed in the direction of an arrow A.
  • Figure 5A is a schematic illustration of an optical arrangement according to a second embodiment of the present invention.
  • Figure 5B is a schematic representation of an optical arrangement according to a third embodiment of the present invention.
  • Figure 6 is a schematic representation of an optical arrangement according to a fourth embodiment of the present invention.
  • Figure 7 is a schematic representation of an optical arrangement according to a fifth embodiment of the present invention.
  • Figure 8 is a schematic representation of an optical arrangement according to a sixth embodiment of the present invention.
  • Figure 9 is a schematic representation, illustrating details of an inclination detecting means used in the Figure 8 embodiment.
  • Figure 10A is a schematic representation of an optical arrangement according to a seventh embodiment of the present invention.
  • Figure 10B is an enlarged schematic view showing a portion of the Figure 10A embodiment.
  • Figure 11 is an explanatory view, showing light emanating from a second physical optic element provided on a first object, in accordance with an aspect of the present invention, as the emanating light is considered wave-optically.
  • Figures 12A and 12B and Figures 13A - 13C are schematic representations, respectively, showing other forms of physical optic elements usable in the present invention.
  • Figure 2 is a schematic representation of an optical arrangement according to an embodiment of the present invention, wherein the invention is applied to a gap measuring device, usable in a semiconductor microcircuit device manufacturing exposure apparatus, for measuring a gap between a mask and a wafer.
  • Figure 3 is a perspective view schematically showing physical optic elements and a portion around them, in the device of the Figure 2 embodiment.
  • Denoted at 1 is a laser beam supplied from a semiconductor laser LD.
  • the semiconductor laser LD may be replaced by a different type of laser device such as a He-Ne laser, for example.
  • Denoted at 2 is a first object which is a mask, for example.
  • Denoted at 3 is a second object which is a wafer, for example.
  • Denoted at 4 and 5 is a first and second physical optic elements which are provided in a portion of the mask 2. Each of these physical optic elements 4 and 5 is provided by a diffraction grating or Fresnel zone plate, for example.
  • Denoted at 7 is a condensing lens having a focal length fs and an optical axis 63.
  • Denoted at 8 is a light receiving means which is disposed at a focal point position of the condensing lens 7.
  • the light receiving means comprises a line sensor, PSD or otherwise and functions to detect the position of the center of gravity of a received light.
  • Denoted at 9 is a signal processing circuit which is operable to determine, by using signals from the light receiving means 8, the position of the center of gravity of the light incident on the light receiving means 8, and to detect by calculation the gap d0 between the mask 2 and the wafer 3 in a manner which will be described later.
  • Denoted generally at 10 is an optical probe comprising the condensing lens 7 and the light receiving means 8 as well as the signal processing circuit 9, as required, which optical probe is movable relatively to the mask 2 and the wafer 3.
  • the light incident on the first Fresnel zone plate 4 is diffracted thereby, and diffraction light of a predetermined order or orders, being diffracted at an angle ⁇ 1 is reflected at a point B (C) on the wafer 3 surface.
  • Reference numeral 31 denotes such a reflection light from the wafer 3 when it is at a position P1 which is at a distance (interval) d0 from the mask 2.
  • Reference numeral 32 denotes such a reflection light from the wafer 3 when it is at a position P2 which is at a distance d G from the position P1.
  • the reflected light from the wafer 3 is incident at a point D (or E as the wafer 3 is at the position P2) on the surface of a second Fresnel zone plate 5 provided in a portion of the first object (mask) 2.
  • the second Fresnel zone plate 5 has an optical function by which the angle of emission of a diffraction light emanating therefrom changes in accordance with the position of incidence of light impinging on the second Fresnel zone plate, like a function of a condensing lens.
  • Diffraction light 61 (or 62 if the wafer 3 is at the position P2) of a predetermined order or orders, being diffracted from the second Fresnel zone plate 5 at an angle ⁇ 2, is directed through the condensing lens 7 onto the surface of the light receiving means 8.
  • the gap or interval between the mask 2 and the wafer 3 can be detected by calculation.
  • each of the first and second Fresnel zone plates 4 and 5 both of which are provided in a portion of the mask 2 has a predetermined pitch. Also, the angle of diffraction ⁇ 1 or ⁇ 2 of the diffraction light of a predetermined order or orders (e.g. positive and negative first orders) produced by reception of light by each Fresnel zone plate, can be detected in preparation.
  • a predetermined order or orders e.g. positive and negative first orders
  • Figure 4A is a top plan view of the Fresnel zone plates (physical optic elements) 4 and 5
  • Figure 4B is a schematic representation of optical paths passing through the physical optic elements 4 and 5, as seen from the direction B
  • Figure 4C is a similar optical path view but as seen from the direction A.
  • the first Fresnel zone plate 4 has a function simply for deflecting a received light. However, it may have a light converging or diverging function.
  • the second Fresnel zone plate 5 is so structured that the direction of diffraction varies with the position on the second Fresnel zone plate.
  • a point 11 corresponds to such a point which is passed by the center of gravity of an emanating light when the interval between the mask 2 and the wafer 3 is 100 microns.
  • the point passed by the emanating light shifts rightwardly in Figure 4A and, when the interval becomes equal to 200 microns, the emanating light passes a point 12.
  • Each Fresnel zone plate has a pattern which, in this embodiment, has no power (light converging or diverging power) in the direction B, as viewed in Figure 4A.
  • the Fresnel zone plate may have a power for allowing adjustment of explanation of light.
  • the interval measurement range for a mask and a wafer is 100 - 200 microns, for example, the size of the area of each Fresnel zone plate 4 or 5 is set so as to be coordinated with the measurement range.
  • the distance d G is detected in accordance with equation (4) and, by using the detected value d G , an error in the wafer 3 position with respect to a reference position (P1) which is at a predetermined or desired interval with respect to the mask 2, to thereby measure an actual interval between the mask 2 and the wafer 3.
  • the position of incidence upon the light receiving means 8 of the light from the second Fresnel zone plate 5, as the wafer 3 is at a desired interval d0 is used as a reference position as seen from the foregoing description.
  • Such reference position can be easily determined in preparation.
  • a suitable means may be used to set a wafer exactly at a predetermined interval (d0) from a mask, and light may be projected from the light source LD.
  • a measuring apparatus "TM-230N" (trade name; manufactured by Canon Inc. Japan) may be conveniently used.
  • the first Fresnel zone plate 4 has a function for deflecting a received light.
  • the angle ⁇ 1 of the light emanating from the first Fresnel zone plate 4 is one of the parameters which determine the sensitivity ⁇ S.
  • the Fresnel zone plate 4 is dismounted so that a light simply transmitted by the mask is used, the angle ⁇ 1 is exactly equal to the angle of incidence of light received by the mask, namely it is exactly in the direction of projection of light from a used light source. In that case, the disposition of light source means is limited to attain a desired sensitivity ⁇ S.
  • a first Fresnel zone plate 4 having a light deflecting function does allow that, for any angle of incidence upon the Fresnel zone plate of a light from a light source, the angle of emission of light emanating from the Fresnel zone plate is easily adjusted to a desired value ⁇ 1 by means of the Fresnel zone plate itself. As a result, the degree of freedom in disposition of a light source means is high.
  • the diameter of a light impinging on the Fresnel zone plate 4 may preferably made slightly larger than the size of the Fresnel zone plate 4. In that case, any displacement of a light incident on the mask surface along the plane of the mask surface does not cause a change in the state of light emanating from the Fresnel zone plate 4.
  • a diffraction light from the second physical optic element 5 which diffraction light is determined with respect to a single position on the wafer 3, is surely incident on the condensing lens 7 at a particular angle with respect to the optical axis 63. Since the light receiving means 8 is provided at the focal point position of the condensing lens 7, the position of incidence of light upon the light receiving means 8 is unchangeable, independently of the position of the optical probe 10 on the optical axis 63 and, additionally, independently of a slight displacement of the optical probe in a direction perpendicular to the optical axis 63. As a result, an error in measurement due to any deviation of the optical probe can be suppressed sufficiently.
  • the condensing lens 7 of the Figure 2 embodiment may be omitted and, in place of this, the optical arrangement may be modified such as illustrated in Figure 5A or 5B. Substantially the same effects are attainable in each case, although the diameter of a light spot incident on the light receiving means 8 is slightly larger as compared with the Figure 2 embodiment.
  • Figure 5A represents an example in which the condensing lens 7 of the Figure 2 embodiment is simply omitted with a slight modification of the position of the light receiving means 8.
  • Figure 5B represents an example wherein a physical optic element 5 such as one used in the Figure 5A example is replaced by one which has an optical function for emitting a received light in a determined direction but which has no light converging function.
  • a diffraction grating comprising a grating formed by parallel linear patterns of regular intervals may be used, for example, as the physical optic element 5.
  • a diffraction grating comprising a grating formed by parallel linear patterns of regular intervals
  • substantially the same advantageous effects are attainable as in the Figure 2 embodiment.
  • the diffraction grating 5 may be omitted so that the reflection light from the wafer 3 simply passes the mask 2, while the light receiving means may be disposed at a suitable position to receive the light passing the mask 2.
  • a light-receiving side diffraction grating 4 in each of the Figure 5A embodiment and the Figure 5B embodiment may be omitted. In that case, light from a light source LD impinges on the mask 2 at an incline with respect to a normal to the mask surface.
  • a diffraction grating may be provided in a portion of the wafer 3, such that the diffracted light from the diffraction grating 4 is diffracted again by that diffraction grating of the wafer 3 toward the second diffraction grating 5 of the mask.
  • Figure 6 is a schematic representation of an optical arrangement according to another embodiment of the present invention, wherein the invention is applied to an X-ray mirror reduction optical system in a semiconductor microcircuit device manufacturing exposure apparatus.
  • a transmission type mask Denoted in Figure 6 at 101 is a transmission type mask; at 102, a wafer which is at a focus position of a reduction optical system; at 102′ and 102 ⁇ , wafers which are at defocused positions, respectively; at 103, an X-ray mirror reduction optical system; at 104, a diffraction grating provided in a portion of the mask 101 and comprising linear patterns of regular intervals; at 105, a light receiving lens; at 106, a photoelectric converting element such as a CCD; at 110, a light (X rays) supplied from an unshown radiation energy source; and at 111, 111′ and 111 ⁇ , are returning lights reflected by the wafer when it is at the positions 102, 102′ and 102 ⁇ , respectively.
  • the X rays projected upon the mask 101 in the direction of an arrow advance along an optical axis 103a of the reduction optical system and irradiate the wafer 102 surface.
  • a pattern formed on the mask 101 can be transferred onto the wafer 102.
  • the position of incidence of a returning light upon the diffraction grating 104 of the mask 101 displaces.
  • the amount of displacement of the position of incidence of light upon the photoelectric converting element 106 is substantially in a proportional relationship with the amount of displacement of the position of the wafer 102 in the direction of the optical axis 103a.
  • the reflected light from the wafer will be incident at a predetermined reference position on the sensor 106.
  • the reflected light from the wafer will be collected at a position shifted from the reference position.
  • the amount of shift in that case is substantially proportional to the amount of the shift of the water position.
  • the reference position may be determined first by bringing a wafer to the position of the predetermined distance by using a suitable wafer position detecting means and second by determining the position of the wafer-reflected light incident in that occasion upon the sensor 106 as the reference position.
  • the light receiving lens 105 functions to project upon the photoelectric converting element 106 the light coming back from the diffraction grating 104.
  • the photoelectric converting element 106 functions to execute signal processing for detecting any difference in light quantity of left hand and right hand spots.
  • the wafer position can be detected.
  • a wafer stage (not shown) is moved in the direction of the optical axis of the reduction optical system to control the focus adjustment.
  • a used mask 101 is a reflection type mask
  • the projection of light upon the first physical optic element 104 is made on the right hand side (X ray emission side) as viewed in Figure 6 and, additionally, the sensing portion (light receiving lens and photoelectric converting element) is also disposed on the same side.
  • Figure 7 is a schematic representation of an optical arrangement according to a further embodiment of the present invention, wherein the invention is applied to a ultraviolet ray reduction optical system in a semiconductor microcircuit device manufacturing exposure apparatus.
  • a mask reticle
  • at 102 a wafer which is at a focus position of a reduction optical system
  • at 102′ and 102 ⁇ wafers which are at defocus positions, respectively
  • at 103′ a ultraviolet-ray reduction optical system (projection lens system)
  • at 104 a diffraction grating provided in a portion of the mask 101
  • at 105 a light receiving lens
  • at 106 a photoelectric converting element
  • at 110 a light supplied from an unshown light source and being projected upon the diffraction grating 104
  • at 111, 111′ and 111 ⁇ returning lights reflected by the wafer as it is at positions 102, 102′ and 102 ⁇ , respectively.
  • the positioned mask and wafer are exactly in an optically conjugate relationship (namely, the wafer is exactly at a focus position), provided that the wavelength of the light 110 is the same as that of the ultraviolet ray used for the pattern printing, the position of the returning light incident upon the mask 101 coincides with the position of incidence of the light 110, coming from the unshown light source. If, however, different wavelengths are used, the returning light coming back from the wafer is incident on the mask 101 at a position shifted from the position of incidence of the light 110 by an amount corresponding to the chromatic aberration. In that case, such a position being shifted is determined at a reference position corresponding to the in-focus state of the wafer. A diffraction grating may be provided at such position to deflect the light toward the photoelectric converting element 106.
  • the interval measuring system of the present embodiment can be called a "TTL (through the lens) type" wherein the interval measurement is made by passing an interval measuring light through a reduction optical system.
  • TTL through the lens
  • the interval measurement is made by passing an interval measuring light through a reduction optical system.
  • Figure 8 is a schematic representation of an optical arrangement according to a yet another embodiment of the present invention, wherein the invention is applied to a ultraviolet-ray reduction optical system in a semiconductor microcircuit device manufacturing exposure apparatus, similarly to the Figure 7 embodiment.
  • Like numerals as in Figure 7 are assigned to similar or corresponding elements.
  • a light receiving lens 105 functions to project upon a photoelectric converting element 106 such a light reflected from a wafer but not passing again a reduction optical system 103.
  • a photoelectric converting element 106 such as a light reflected from a wafer but not passing again a reduction optical system 103.
  • a half mirror 107 and an additional photoelectric converting element 108 such as a PSD sensor or a CCD sensor which is of a type that the position of incidence of a received light can be discriminated.
  • the photoelectric converting device 108 is disposed at a focal point position of the lens 105 (more exactly, at a position which is optically equivalent to the focal point position).
  • ⁇ x is proportional to ⁇ x′ which represents the amount of shift of the light 111 incident upon the photoelectric converting device 106 as resulting from the same inclination of the wafer
  • Figure 10A is a schematic representation of an optical arrangement according to seventh embodiment of the present invention.
  • Figure 10B is an enlarged view schematically showing a portion of the optical path as defined by the optical arrangement of Figure 10A.
  • Like numerals as in Figure 2 are assigned to corresponding or similar elements.
  • each of physical optic elements 4 and 5 is provided by a Fresnel zone plate having a light converging or diverging function.
  • the focal length of the second Fresnel zone plate 5 is f M2 (micron) (wherein the value of f M2 may be either positive or negative); the distance from the second Fresnel zone plate 5 to a light evaluation plane 8a which corresponds to a sensor 8 surface is l; the diameter of light upon the second Fresnel zone plate 5 is ⁇ 1; the diameter of light upon the light evaluation plane 8a is ⁇ 2; and the light projected upon the second Fresnel zone plate 5 is a parallel light.
  • the diameter ⁇ 2 is very large if l > > f M2 .
  • the refracting powers of the first and second Fresnel zone plates 4 and 5 are so set that, when the mask 2 and the wafer 3 are disposed exactly at a preset interval d, the light from the second Fresnel zone plate 5 is imaged upon a single point on the light evaluation plane 8a, as illustrated in Figure 10B, so as to reduce the diameter ⁇ 2 on the evaluation plane 8a to ensure high-precision detection of the position of the center of gravity of light by the sensor 8a.
  • the actual beam-waist position comes nearer to the Fresnel zone plate 5 side, as compared with the geometro-optic focus position of the light.
  • Such actual beam waist position is almost determined by the beam diameter and, therefore, the adjustment thereof is difficult to achieve.
  • the difference between the beam waist diameter and the beam diameter at the geometro-optic focus position is so large that can not be practically disregarded as being null, it means that the beam waist position is close to the Fresnel zone plate 5. Thus, it is difficult to define the light evaluating plane at this position.
  • the diameter ⁇ 2 becomes minimum when R1 ⁇ l.
  • the value f M1 is so set as to satisfy the relation "R1 ⁇ l" where the expansion of the beam diameter ⁇ 2 upon the sensor 8a surface is treated wave-optically.
  • Figures 12A and 12B are schematic representations, illustrating in development views, optical paths arranged in accordance with an eighth and ninth embodiments of the present invention.
  • Reference numeral 161 denotes light.
  • a wafer used is omitted in these drawings.
  • Figure 12A shows an example wherein each of a light-reception side first Fresnel zone plate 4 and a light-emission side second Fresnel zone plate 5, both being provided in a portion of a first object 2, has a light converting function or a convex-lens function.
  • Figure 12B shows an example wherein a light-reception side first Fresnel zone plate 4 has a convex-lens function, while a light-emission side second Fresnel zone plate 5 has a diverging or concave-lens function. In either case, substantially the same advantageous results as by the Figure 10A embodiment are attainable.
  • Figures 13A - 13C are schematic representations, illustrating in development views the optical paths defined in accordance with a tenth, eleventh and twelfth embodiments of the present invention.
  • Figure 13A shows an example wherein a converging light is incident on the first Fresnel zone plate 4.
  • the first Fresnel zone plate 4 functions as a concave lens
  • the second Fresnel zone plate 5 functions as a convex lens.
  • Figure 13B shows an example wherein a divergent light is incident upon a first Fresnel zone plate 4.
  • the first Fresnel zone plate 4 functions as a concave lens
  • the second Fresnel zone plate 5 functions as a convex lens.
  • Figure 13C shows an example wherein a parallel light is incident upon a first Fresnel zone plate 4. At this time, it functions as a concave lens, while the second Fresnel zone plate 5 functions as a convex lens.
  • Reference numeral 162 denotes wave surface of the light.
  • the shape of the first or second Fresnel zone plate is so set as to cancel any wavefront aberration when a light having such wavefront aberration is incident thereupon.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
  • Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)
  • Length Measuring Devices By Optical Means (AREA)

Claims (7)

  1. Dispositif pour mesurer la distance (do) entre des premier (2, 101) et second (3, 102) objets analogues à des plaques, disposés sensiblement parallèlement l'un à l'autre, comportant une source de lumière (LD) destinée à projeter un faisceau lumineux (1, 110) sur le premier objet (2, 101), lequel faisceau est ensuite projeté sur le second objet (3), et un photodétecteur (8) destiné à détecter la position d'incidence, sur sa surface de détection, du faisceau lumineux ayant été réfléchi par le second objet ;
       caractérisé par un élément optique (4, 5, 104) sous la forme d'un élément de diffraction ou d'une plaque à zone de Fresnel positionné sur ledit premier objet (2, 101) de manière que le faisceau lumineux détecté par ledit photodétecteur soit un faisceau lumineux (6 ; 61 ; 62) ayant été dévié par ledit élément optique en amont ou en aval de la position de réflexion sur le second objet par rapport au sens du faisceau, grâce à quoi la position d'incidence du faisceau lumineux sur la surface de détection du photodétecteur varie avec la distance entre les deux objets, et un processeur (9) de signaux comprenant des moyens destinés à recevoir le signal de sortie du photodétecteur (8) et à générer un signal représentant un déplacement relatif entre lesdits objets, et des moyens destinés à comparer ledit signal généré à un signal de référence correspondant à une distance prédéterminée entre lesdits objets pour déterminer la distance les séparant sur la base de la comparaison.
  2. Dispositif selon la revendication 1, caractérisé en ce que ledit élément optique (5) disposé en aval de la position de réflexion remplit une fonction de lentille de condensation.
  3. Dispositif selon la revendication 1 ou 2, caractérisé en ce que ledit photodétecteur (8) détecte le faisceau lumineux ayant été diffracté par ledit élément optique (4) sur le premier objet (2), réfléchi par le second objet (3) et ensuite diffracté par un second élément optique (5) sur le premier objet (2).
  4. Dispositif selon la revendication 1, 2 ou 3, pour produire un dispositif semiconducteur dans lequel les premier et second objets sont respectivement un masque à motif et une tranche,
       caractérisé par des moyens pour aligner le masque et la tranche sur la base de la détermination de distance, et un système (103) d'impression destiné à imprimer un motif du masque (2, 101) sur la tranche (3, 102).
  5. Système selon la revendication 4, caractérisé en ce que ledit système d'impression comprend un système optique (103) à rayons X.
  6. Système selon la revendication 4, caractérisé en ce que ledit système d'impression comprend un système optique (103′) à rayons ultraviolets.
  7. Procédé de fabrication de dispositifs semiconducteurs, comprenant les étapes qui consistent :
       à utiliser un masque (2, 101) ayant un motif et un élément optique (5, 104) sous la forme d'un élément de diffraction ou d'une plaque à zone de Fresnel sur ledit premier objet ;
       à utiliser une tranche (3, 102) ;
       à projeter un faisceau lumineux (1, 110) sur le masque (2, 101) et la tranche (3, 102) ;
       à détecter la position d'incidence, sur un plan prédéterminé, du faisceau lumineux ayant été réfléchi par la tranche (3, 101) et ayant été dévié par l'élément optique (5, 104) du masque (2, 101) soit en amont, soit en aval de la position de réflexion sur la tranche par rapport au sens du faisceau ;
       à déterminer la distance entre le masque (2, 101) et la tranche (3, 102) sur la base de la détection au moyen d'un processeur (9) de signaux qui comprend des moyens destinés à générer un signal représentant un déplacement relatif entre ledit masque et ladite tranche et des moyens destinés à comparer ledit signal à un signal de référence correspondant à une distance prédéterminée entre ledit masque et ladite tranche ;
       à aligner le masque (2, 101) et la tranche (3, 102) sur la base de la détermination par ledit processeur de signaux ; et, ensuite,
       à effectuer une impression du motif du masque (2, 101) sur la tranche (3, 102).
EP89301473A 1988-02-16 1989-02-16 Procédé et dispositif pour la mesure d'un intervalle entre deux objets Expired - Lifetime EP0332300B1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP3320688 1988-02-16
JP33206/88 1988-02-16
JP22581088 1988-09-09
JP225810/88 1988-09-09

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EP0332300A2 EP0332300A2 (fr) 1989-09-13
EP0332300A3 EP0332300A3 (en) 1989-10-11
EP0332300B1 true EP0332300B1 (fr) 1995-06-14

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DE (1) DE68923018T2 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2756331B2 (ja) * 1990-01-23 1998-05-25 キヤノン株式会社 間隔測定装置

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61111402A (ja) * 1984-11-06 1986-05-29 Nippon Kogaku Kk <Nikon> 位置検出装置

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0666241B2 (ja) * 1985-10-14 1994-08-24 株式会社日立製作所 位置検出方法
DE3719538A1 (de) * 1986-06-11 1987-12-17 Toshiba Kawasaki Kk Verfahren und vorrichtung zum einstellen eines spalts zwischen zwei objekten auf eine vorbestimmte groesse

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61111402A (ja) * 1984-11-06 1986-05-29 Nippon Kogaku Kk <Nikon> 位置検出装置

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
OPTICAL ENGINEERING, vol. 22, no. 2, March/April 1983, pp. 203-207, Bellingham, Washington, USA ; M. FELDMAN et al. : "Application of zone plates to alignment in x-ray lithography" *

Also Published As

Publication number Publication date
DE68923018T2 (de) 1995-11-09
DE68923018D1 (de) 1995-07-20
EP0332300A3 (en) 1989-10-11
EP0332300A2 (fr) 1989-09-13

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